The present invention relates to methods of working, especially of polishing, surfaces of materials composed of at least two components or ingredients.
A typical example of a material composed of two different components is the glass ceramic material, Zerodur®, which has a crystalline phase with a negative thermal expansion coefficient and a glass phase with a positive thermal expansion coefficient. Both phases have different erosion properties.
In the known working method effects described in the following occur during and/or after the working of the surface. First, the surface is polished at a definite working temperature until a minimum polish roughness is reached during the polishing. The polish roughness results predominantly from the different erosion properties of both components. Since the application temperature of the material usually varies from the working temperature, the surface roughness is increased in relation to the polish roughness because of the differing thermal expansion coefficients because of the differing thermal expansion properties of both components, so that the quality of the surface of the material no longer corresponds to the required specification.
For example, the material used for making wafers must have a surface roughness of less than 2 Å. It has not been possible to achieve this currently.